Question

Which of the following is(are) not the square of a 3 × 3 matrix with real entries?

Answer 1

(B, D) In options (A) and (C) |A²| = 1 and in option (B) and (D) |A²| = – 1
We know |A²| = |A|² and |A|² ≠ –1 => matrices given in options B & D cannot be the squares of any 3 × 3 matrix with real entries.